> the data showed that on summit night, the average body temperature difference between the twin in modern down and the twin in complicated layers of silk, wool, and gabardine was a staggering 1.8°C.
> “In a hundred years, you’ve gained—arguably—one degree of efficiency per 50 years,” Ross reveals.
Depending on where the baseline is, 1.8 degrees could be huge! But more importantly, heat dissapation is a non-linear function. The warmer you are relative to your environment, the more energy is lost. While Shackleton's kit forms a lower baseline, it probably makes sense to imagine how some imaginary perfect vacuum insulated sleeping bag would perform.
Depending on where the baseline is, 1.8 degrees could be huge! But more importantly, heat dissapation is a non-linear function. The warmer you are relative to your environment, the more energy is lost. While Shackleton's kit forms a lower baseline, it probably makes sense to imagine how some imaginary perfect vacuum insulated sleeping bag would perform.